Commonwealth's urban upper layer had lost its previously prominent role in the promotion of cultural advancement, but in Silesia, where Polish gentry no longer existed, Protestant townspeople continued Polish language educational and cultural activities, including literary work and publications, in several cities. Toward the middle of the 18th century the Polish and German burghers of Danzig, Thorn (Toruń) and other municipalities of Royal Prussia were among the pioneers of Polish Enlightenment. The typically parochial climate of ignorance, backwardness and prejudice in many small towns found its expression in a number of witch trials. Many magnate residencies were built and public improvement projects completed in Warsaw during the first half of the 18th century. Beginnings of recovery The first changes indicating an upcoming economic recovery took place in the 1725–50 period. More clearly visible agricultural and industrial progress occurred during the two following decades (1750–70) and had to do with the improved by that time state of the agricultural market in Europe. During the earlier period some technical advances were made and contributed to improved agriculture and, more importantly, the nature of rural social relations was changing. Beginning in Poznań region and then elsewhere in western Greater Poland and Royal Prussia, the manorial serfdom labor requirements were being replaced with peasant land rentals and owners collecting monetary compensation. This "buying off" of the forced labor obligations was often favored by the peasants themselves, as it improved their financial situation and reconnected them to city markets. The same two regions and the capital city of Warsaw experienced also a moderate awakening in the area of industrial activities and urban business enterprises. A major trading house was established in Warsaw by French Huguenots in 1723. Manufacturing businesses were created by a number of magnates in various regions. Among the most important was the developing iron industry in southern and central Poland (Old-Polish Industrial Region). These modest signs of industrial progress occurred within the Commonwealth with a nearly half-century delay not only in comparison to Poland's western and southern neighbors, but also with respect to Russia. Wars fought to protect territorial integrity, decline of government Khmelnytsky Uprising, peasant movements, Cossack alliance with Russia The long-lasting Cossack uprising began in 1648 and was led by Bohdan Khmelnytsky. It was a great national and social movement, as the increasingly exploited Rus' peasant masses joined the Cossacks to fight their szlachta oppressors. Polonization, catholicizing, state support for